Interlock mechanism



y 1942- E. J. MASTNEY 2,289,513

INTERLOCK MECHANISM Filed March 29, 1940 2 Sheets-Sheet l H c z rizi m' L 26 2; i/Zdkf/ J/kwf/ze Patented July 14, 1942 INTERLOCK MECHANISM Edward J. Mastney, Berwyn, IlL, assignor to .Oak

Manufacturing Company, a corporation of Illinois Application March 29, 1940, Serial N0.I32'6,580

1 Claim.

This invention relates to an interlock mechanism but may be used for electric switching and the like. The mechanism provides a plurality of push button controls movable between two positions. Means are provided whereby each button may be independently locked into a pushed position or may be returned to its free position and in case of the former, means may be provided whereby previously locked push buttons may be unlocked or not as desired.

The interlock mechanism described herein may be used with the switching mechanisms described andclaimed in the application of Edward J. Mastney et al., Serial No, 180,742, filed December 20, 1937, or of Kenneth C. Allison, Serial No. 231,399, filed September 23, 1938. The interlock mechanism described herein is an improvement on the interlocking mechanism described in both of the applications above referred to.

Referring to the drawings:

Figure 1 is an elevation view of the mechanism with all parts in a normal position;

Fig. 2 is a detail of the mechanism of Fig. 1 with the locking push rod down into position and several push rods locked thereby;

Fi 3 is a detail view of the left hand end-of the mechanism shown in Fig. 1 with the unlocking rod operated to release all the previously locked push rods;

Fig. 4 is a sectional view on-line 4-4 of Fig. 1;

Fig. 5 is-a sectional View on line 5-5 of Fig. 1 and showing switching elements operated by the switch mechanism;

Fig. 6 is a section on line 6-'6 of Fig. 5;

Fig. 7 is'a section similar to-Fig. 6 but taken at right angles to the plane of red 2112 and through its longitudinal axis.

Fig. 8 is a section on line 88 of Fig. 7.

The mechanism is made of steel Or other suitable material and in general comprises a front channel shaped member lil having turned up edges II and I2 and a rear channel shaped member [5 having turned up edges 16 and I1, both forming spaced members rigidly maintained in position by end members I8 and [9 respectively. End members [8 and I9 may be fastenedtogether to the base members and in any suitable fashion. As clearly indicated in Figs 2 and 3, end members [8 and I9 have their sides bent outwardly to form flanges 20 and 2| respectively.

Front member is provided with a plurality of spaced parallel slots 24 extending transversely thereof while rear member I5 is provided with similar slots 25, one slot of each series being adapted to register with a slot of the other series to form a cooperating pair of slots. Slidably disposed in each pair of slots are unlocking push rod 21, switch operating push rods 21a and locking push rod 271), push rods 21a being all similar While '2'! and 21b differ from each other and from push rod 21a.

Referring particularly to Fig. 4, unlocking push rod 21 is provided with a body portion 28 and a handle portion'29. Body portion 28 has a long narrow slot 3! at one portion thereof and a large cutout 32 near the bottom end thereof. Cutout 32 is of such a shape as to leave opposing fingers 33 and 34 therein, finger 34 being longer and extending through one of the slots 25 in bottom or rear base member 15. A coil spring 35 is disposed around the opposing fingers 33 and 34 between the body 28 of the push rod and the inside of channel member I 5 'and is adapted to bias the entire push rod toward the front, that is in the position shown in Fig. '1. As clearly shown in Fig. 3, however, push rod 21 vmay be pushed against the bias of spring 35 to a rear position.

The rear position of push rod 2'! and for that matter of all the push rods is limited by the intersection of one upturned edge ll of rearbase member l5 striking the body portion of the push rod.

Push rod 21 may have a felt or rubber Washer 31 between the body and inside of front base member Iii to silence the push rod on the return stroke. The push rod is also provided with a plurality of ears 38 and a large ear 39 on each side thereof on which may be loosely mounted a sheet of insulation 40 (to carry contacts) that may be pushed backward and forward during the operation of the rod. As shown in Fig. 5, a stationary insulating member 41' having contacts cooperates with movable member 40.

Push rods 2m are generally similar to push rod 2'! in having a handleportion'ZB and a cutout portion 32 with opposing fingers 33 and 34 and a coil spring'35. The difference between rods 21a and rod 2! lies in the body portion 28 wherein an elongated slo-t 3| is provided. S-lot3l is substantially longer than slot 3| in rod 27, the two slots being normally aligned'with regard to the side thereof and the rear'portion thereof, that is nearest the bottom of the push rod, slots 3|" however extending nearer the front base member [0 than slot 3| does. This comparison of course is made with all the rods aligned.

Each push rod 21a has riveted thereto, as for example at 33', a fiat spring 42 having an end portion 43 and a cutout 44. Spring 42 is normally disposed to lie against body 28' of the push rod and by virtue of a lip 45 at end portion 43, long slot 3I is divided into a small forward or upper locking slot 46 and a long rear or bottom slot 41. Long slot 41 has substantially the same length as slot 3| in rod 21.

Locking push rod 2112 has the same general construction as push rods 21 and 21a as far as the finger portion 29 and spring supporting portions 33 and 34 within a cutout. The body portion I28 however has a slot I3I which is identical with slot 3| of rod 21 and in addition thereto has a locking slot I46 normally registering with slot 46, the two slots in this rod being punched to leave an intervening partition I45.

Slidably disposed in the end members and threaded through the push rods is a locking bar 50 having a smooth rear edge I and a plurality of serrations 52 on the opposite side thereof. The serrations 52 correspond with the push rods 21 to 21b inclusive, there being one serration for each push rod. Each serration comprises a generally straight sloping portion 53 with a tip 54 which goes down into a recessed locking portion 55 and then joins the straight portion 53 of the next serration. One end of locking bar 56 is reduced as at 51 and is provided with a coil spring 58 around said portion as it extends beyond end member I9. Coil spring 58 cooperates with end member I 9 to bias the locking bar in the position shown in Fig. 1.

With all the rods shown in the position in Fig. l the large slot of each of the push rods register suiiiciently to accommodate the tip 54 of each serration. The unlocking slots are adapted to register with serration tip 54 in the depressed position of a push rod.

Push rod 21b has riveted thereto at I33 a spring I41 bent into the shape shown in Fig. 7 and adapted to press against straight portion 53 of the adjacent serration when the rod is pushed down into locking position.

When unlocking rod 21 is pushed to the position shown in Fig. 3, slot 3| goes out of registry with the locking bar with the result that the body portion 28 of the push rod acting upon the tip 54 of the corresponding serration forces the locking bar to the left to an unlocking position. Hence, every tip 54 is moved sideways and out of the corresponding push rod interior and the result is that every push rod is unlocked and permitted to return to its front position in response to the bias of its coil spring 35, if not there already. Unlocking rod 21 not having a locking slot will always return when released.

When one of the push rods 21a is depressed and the locking bar is in the position shown in Fig. 1, then the corresponding slot 41 is thrown out of alignment. Thus referring to Figs. 5 and 6 when the push rod is operated, separating lip 45 carried by the spring 42 is pushed past the locking tip 54 of the particular serration. Spring 42 is stiff enough so that the locking bar will yield due to the cam action of the locking tip 54 of that particular serration. Then the locking tip can move back into small slot 46. At the same time any of the rods 21a which may have been locked previously are permitted to return due to the unlocked portion of the locking bar.

In the event that push rod 21b is pushed into locking position, tip 54 of the serration goes into small slot I46 while spring I41 is pushed into the dotted line position to engage the straight portion 53 of the adjacent serration. This spring I41 is sufiiciently stiff to hold the locking bar in the locked position shown in Fig. 1 irrespective of subsequent operation of push rods 21a. Hence if any of the push rods 21a are now pushed down, the locking bar 56 will not yield but will force spring 42 to flex out of the way and permit the locking tip to go into small locking aperture 44'. Hence any of the push rods 21a will remain in a locked position. The entire mechanism including all push rods 21a and locking rod 211) may be released by pressing on rod 21. Since rod 21 does not have any locking aperture the action of the front edge of slot 3I on the locking tip 54 of the bar will force the locking bar to clear all rods 21a and rod 211) and permit them to return. Spring I41 also snaps back into its clear unlocked position.

What is claimed is:

An interlock mechanism for switches or the like,.said mechanism comprising a base having a plurality of parallel push rods movable therein between two end positions, said rods having aligned body portions, one of said rods being an unlocking rod, another being a locking rod and remainder being normal operating rods, means for biasing every one of said rods to one position, each rod having a slot in the body thereof to form a series of aligned slots in said one position, a locking bar threaded through said series of rod slots, said locking bar being movable lengthwise transversely of said rods between a locking and unlocking position, said bar having a serration for each rod, each serration normally extending into the slot region of each rod when said rod is in its one position and when the bar is in the locking position, the slots being small so that when a rod is pushed into another position, said serration is normally forced out of the rod slot to move the bar to an unlocking position, said locking and remaining rods having an additional locking slot in the body thereof, said locking slots forming a second series of aligned slots parallel to the first series when the ends are in the same position, each first mentioned slot and locking slot being aligned along the direction of rod movement, a serration being adapted to extend into a locking slot when the corresponding rod is in its other position and said locking bar is in its locking position, means for biasing said locking bar to a locking position, the remaining rods each having a spring member to form the two slots, said spring member being deflectable to permit the push rod to reach its other position in the event that the locking bar does not go to an unlocking position, means on said locking rod for retaining the locking bar in a locked position and retaining said rod in its other position irrespective of the movement of the remaining rods, said unlocking rod however forcing said locking bar to a position for releasing both the locking bar and locking rod when said unlocking rod is moved to its other position.

EDWARD J. MASTNEY. 

